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INTRODUCTION: Congenital factor V (FV) deficiency is a rare clotting disorder affecting â¼1 in 1,000,000, with bleeding severity that ranges broadly for poorly understood reasons. AIM: To help understand the molecular basis of the observed phenotype in FV deficient patients, the genetics and biochemistry causing a patient's FV deficiency were evaluated. METHODS AND RESULTS: A 71-year-old female, who had serious life-long bleeding upon provocation and profound menorrhagia that lead to hysterectomy, was found to have 3% of normal plasma FV antigen with normal electrophoretic mobility. Platelet FV was similarly low, although the banding pattern was less fragmented than normal. Plasma clotting activity was <1% of normal. Familial inheritance and DNA sequence analysis from peripheral blood leukocytes were consistent with novel compound heterozygosity with missense mutations in exon XVII, Leu1821 to Ser (L1821S) and exon XXV, Gly2192 to Cys (G2192C). The respective single-mutation variants were expressed and purified. Explaining why the antigen level and activity were inequivalent, thrombin activation of recombinant (r) FV/L1821S was impaired, and rFV/G2192C was unable to bind to a procoagulant phospholipid membrane. CONCLUSION: These findings are consistent with the observed phenotype, highlighting the importance of understanding FV biochemical function to rationalize clinical bleeding severity when the circulating antigen level is discordant.
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Thrombotic disease may be an underdiagnosed condition of prolonged exposure to microgravity and yet the underlying factors remain poorly defined. Recently, an internal jugular vein thrombosis was diagnosed in a low-risk female astronaut after an approximately 7-week space mission. Six of the additional 10 crew members demonstrated jugular venous flow risk factors, such as suspicious stagnation or retroversion. Fortunately, all were asymptomatic. Observations in space as well as clinical and in vitro microgravity studies on Earth, where experiments are designed to recapitulate the conditions of space, suggest effects on blood flow stasis, coagulation, and vascular function. In this article, the related literature on thrombotic disease in space is reviewed, with consideration of these elements of Virchow's triad.
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Trombosis , Ingravidez , Humanos , Femenino , Ingravidez/efectos adversos , Coagulación Sanguínea , Venas Yugulares , HemodinámicaRESUMEN
Even with extensive transfusion support, trauma-induced bleeding often leads to death. Early intervention may improve outcomes, yet which blood products, factor concentrates, or other drugs constitute optimal treatment is unclear. Patients with acute traumatic coagulopathy (ATC), arising from trauma and haemorrhagic shock, have the worst prognosis. Here, multiple interventions were compared in a mouse model of ATC. After the trauma of tissue excision, anaesthetized mice were bled to 35 mm Hg mean arterial pressure, maintained under shock for 60 min, and resuscitated with fluids equal in volume to the shed blood. Resuscitated mice were subjected to liver laceration to test haemostasis and blood loss was quantified. Saline-treated mice lost two- to three-fold more blood than sham-treated animals and were coagulopathic by prothrombin time elevation post- versus pre-procedure. Murine fresh-frozen plasma (mFFP), anti-activated protein C aptamer HS02-52G, or prothrombin complex concentrates eliminated the bleeding diathesis and coagulopathy; fibrinogen, plasminogen activator inhibitor-1, or tranexamic acid ameliorated bleeding or coagulopathy, but not both. HS02-52G and mFFP also eliminated the changes in plasma aPC and tissue plasminogen activator levels observed in saline-treated mice, as judged via microtiter plate biomarker assays. Procoagulant interventions, especially inhibiting aPC, could be beneficial in human ATC.
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In 1969, Dr. Oscar Ratnoff, a pioneer in delineating the mechanisms by which coagulation is activated and complement is regulated, wrote, "In the study of biological processes, the accumulation of information is often accelerated by a narrow point of view. The fastest way to investigate the body's defenses against injury is to look individually at such isolated questions as how the blood clots or how complement works. We must constantly remind ourselves that such distinctions are man-made. In life, as in the legal cliché, the devices through which the body protects itself form a seamless web, unwrinkled by our artificialities." Our aim in this review, is to highlight the critical molecular and cellular interactions between coagulation and complement, and how these two major component proteolytic pathways contribute to the seamless web of innate mechanisms that the body uses to protect itself from injury, invading pathogens and foreign surfaces.
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Proteínas del Sistema Complemento , Trombosis , Coagulación Sanguínea , Comunicación Celular , Proteínas del Sistema Complemento/metabolismo , HumanosRESUMEN
PURPOSE OF REVIEW: COVID-19 remains a major source of concern, particularly as new variants emerge and with recognition that patients may suffer long-term effects. Mechanisms underlying SARS-CoV-2 mediated organ damage and the associated vascular endotheliopathy remain poorly understood, hindering new drug development. Here, we highlight selected key concepts of how the complement system, a major component of innate immunity that is dysregulated in COVID-19, participates in the thromboinflammatory response and drives the vascular endotheliopathy. RECENT FINDINGS: Recent studies have revealed mechanisms by which complement is activated directly by SARS-CoV-2, and how the system interfaces with other innate thromboinflammatory cellular and proteolytic pathways involving platelets, neutrophils, neutrophil extracellular traps and the coagulation and kallikrein-kinin systems. With this new information, multiple potential sites for therapeutic intervention are being uncovered and evaluated in the clinic. SUMMARY: Infections with SARS-CoV-2 cause damage to the lung alveoli and microvascular endothelium via a process referred to as thromboinflammation. Although not alone in being dysregulated, complement is an early player, prominent in promoting the endotheliopathy and consequential organ damage, either directly and/or via the system's complex interplay with other cellular, molecular and biochemical pathways. Delineating these critical interactions is revealing novel and promising strategies for therapeutic intervention.
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COVID-19 , Trampas Extracelulares , Trombosis , Proteínas del Sistema Complemento , Humanos , Inflamación , SARS-CoV-2 , Trombosis/etiologíaRESUMEN
Critically injured persons suffer trauma, hemorrhage, and high mortality. A subset of such patients develops early coagulation dysfunction characterized as acute traumatic coagulopathy (ATC), with a poor prognosis. The mechanisms contributing to ATC remain incompletely understood. Notwithstanding some successes in conducting clinical trials in early traumatic coagulopathy, conducting clinical research in ATC is ethically and logistically challenging. In vitro studies cannot capture the complex pathophysiological interplay between blood, vasculature, and organ systems relevant to ATC. Animal models are therefore vital for understanding ATC and to test interventions. Previous systematic reviews of animal models of ATC covered progress up to 2014. The current review aimed to extend that coverage to the end of 2021. A structured systematic search of MEDLINE/PubMed was carried out and identified 56 relevant publications. Unlike in previous reviews, where pig models predominated, rat and pig models contributed equally (19 studies each), and non-human primate models entered the field. Most studies now featured defined trauma (39 of 56), and hemorrhage controlled by pressure or volume (42 studies), with some documenting that both were necessary to induce ATC. Most studies documented coagulopathy using clotting or viscoelastometric assays and created an endogenous coagulopathy not dependent on iatrogenic dilution. As before, the diversity of species and experimental protocols may limit the translatability of the identified studies. Thus, while animal research has become more aligned to clinical realities since 2014, further efforts are required to unravel ATC mechanisms and enable the prediction and evaluation of optimal clinical interventions.
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Trastornos de la Coagulación Sanguínea , Heridas y Lesiones , Animales , Coagulación Sanguínea , Trastornos de la Coagulación Sanguínea/etiología , Modelos Animales de Enfermedad , Hemorragia , Humanos , Ratas , Porcinos , Heridas y Lesiones/complicacionesRESUMEN
Mechanisms underlying the SARS-CoV-2-triggered hyperacute thrombo-inflammatory response that causes multi-organ damage in coronavirus disease 2019 (COVID-19) are poorly understood. Several lines of evidence implicate overactivation of complement. To delineate the involvement of complement in COVID-19, we prospectively studied 25 ICU-hospitalized patients for up to 21 days. Complement biomarkers in patient sera and healthy controls were quantified by enzyme-linked immunosorbent assays. Correlations with respiratory function and mortality were analyzed. Activation of complement via the classical/lectin pathways was variably increased. Strikingly, all patients had increased activation of the alternative pathway (AP) with elevated levels of activation fragments, Ba and Bb. This was associated with a reduction of the AP negative regulator, factor (F) H. Correspondingly, terminal pathway biomarkers of complement activation, C5a and sC5b-9, were significantly elevated in all COVID-19 patient sera. C5a and AP constituents Ba and Bb, were significantly associated with hypoxemia. Ba and FD at the time of ICU admission were strong independent predictors of mortality in the following 30 days. Levels of all complement activation markers were sustained throughout the patients' ICU stays, contrasting with the varying serum levels of IL-6, C-reactive protein, and ferritin. Severely ill COVID-19 patients have increased and persistent activation of complement, mediated strongly via the AP. Complement activation biomarkers may be valuable measures of severity of lung disease and the risk of mortality. Large-scale studies will reveal the relevance of these findings to thrombo-inflammation in acute and post-acute COVID-19.
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COVID-19 , Biomarcadores , Activación de Complemento , Mortalidad Hospitalaria , Humanos , Hipoxia , SARS-CoV-2RESUMEN
BACKGROUND: CD248 is a pro-inflammatory, transmembrane glycoprotein expressed by vascular smooth muscle cells (VSMC), monocytes/macrophages, and other cells of mesenchymal origin. Its distribution and properties are reminiscent of those of the initiator of coagulation, tissue factor (TF). OBJECTIVE: We examined whether CD248 also participates in thrombosis. METHODS: We evaluated the role of CD248 in coagulation using mouse models of vascular injury, and by assessing its functional interaction with the TF-factor VIIa (FVIIa)-factor X (FX) complex. RESULTS: The time to ferric chloride-induced occlusion of the carotid artery in CD248 knockout (KO) mice was significantly longer than in wild-type (WT) mice. In an inferior vena cava (IVC) stenosis model of thrombosis, lack of CD248 conferred relative resistance to thrombus formation compared to WT mice. Levels of circulating cells and coagulation factors, prothrombin time, activated partial thromboplastin time, and tail bleeding times were similar in both groups. Proximity ligation assays revealed that TF and CD248 are <40 nm apart, suggesting a potential functional relationship. Expression of CD248 by murine and human VSMCs, and by a monocytic cell line, significantly augmented TF-FVIIa-mediated activation of FX, which was not due to differential expression or encryption of TF, altered exposure of phosphatidylserine or differences in tissue factor pathway inhibitor expression. Rather, conformation-specific antibodies showed that CD248 induces allosteric changes in the TF-FVIIa-FX complex that facilitates FX activation by TF-FVIIa. CONCLUSION: CD248 is a newly uncovered protein partner and potential therapeutic target in the TF-FVIIa-FX macromolecular complex that modulates coagulation.
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Tromboplastina , Trombosis de la Vena , Animales , Antígenos CD , Antígenos de Neoplasias , Factor VIIa , Humanos , Ratones , Ratones Noqueados , Tiempo de ProtrombinaRESUMEN
In December 2019, the world was introduced to a new betacoronavirus, referred to as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for its propensity to cause rapidly progressive lung damage, resulting in high death rates. As fast as the virus spread, it became evident that the novel coronavirus causes a multisystem disease (COVID-19) that may involve multiple organs and has a high risk of thrombosis associated with striking elevations in pro-inflammatory cytokines, D-dimer, and fibrinogen, but without disseminated intravascular coagulation. Postmortem studies have confirmed the high incidence of venous thromboembolism, but also notably revealed diffuse microvascular thrombi with endothelial swelling, consistent with a thrombotic microangiopathy, and inter-alveolar endothelial deposits of complement activation fragments. The clinicopathologic presentation of COVID-19 thus parallels that of other thrombotic diseases, such as atypical hemolytic uremic syndrome (aHUS), that are caused by dysregulation of the complement system. This raises the specter that many of the thrombotic complications arising from SARS-CoV-2 infections may be triggered and/or exacerbated by excess complement activation. This is of major potential clinical relevance, as currently available anti-complement therapies that are highly effective in protecting against thrombosis in aHUS, could be efficacious in COVID-19. In this review, we provide mounting evidence for complement participating in the pathophysiology underlying the thrombotic diathesis associated with pathogenic coronaviruses, including SARS-CoV-2. Based on current knowledge of complement, coagulation and the virus, we suggest lines of study to identify novel therapeutic targets and the rationale for clinical trials with currently available anti-complement agents for COVID-19.
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Coagulación Sanguínea , COVID-19/inmunología , Activación de Complemento , Proteínas del Sistema Complemento/inmunología , SARS-CoV-2/inmunología , Trombosis/inmunología , Animales , Anticoagulantes/uso terapéutico , Coagulación Sanguínea/efectos de los fármacos , COVID-19/sangre , COVID-19/virología , Activación de Complemento/efectos de los fármacos , Inactivadores del Complemento/uso terapéutico , Interacciones Huésped-Patógeno , Humanos , Trombosis/sangre , Trombosis/prevención & control , Trombosis/virología , Tratamiento Farmacológico de COVID-19RESUMEN
The activated form of coagulation factor XIII (FXIII-A2B2), FXIII-A*, is a hemostatic enzyme essential for inhibiting fibrinolysis by irreversibly crosslinking fibrin and antifibrinolytic proteins. Despite its importance, there are no modulatory therapeutics. Guided by the observation that humans deficient in FXIII-B have reduced FXIII-A without severe bleeding, we hypothesized that a suitable small interfering RNA (siRNA) targeting hepatic FXIII-B could safely decrease FXIII-A. Here we show that knockdown of FXIII-B with siRNA in mice and rabbits using lipid nanoparticles resulted in a sustained and controlled decrease in FXIII-A. The concentration of FXIII-A in plasma was reduced by 90% for weeks after a single injection and for more than 5 months with repeated injections, whereas the concentration of FXIII-A in platelets was unchanged. Ex vivo, crosslinking of α2-antiplasmin and fibrin was impaired and fibrinolysis was enhanced. In vivo, reperfusion of carotid artery thrombotic occlusion was also enhanced. Re-bleeding events were increased after challenge, but blood loss was not significantly increased. This approach, which mimics congenital FXIII-B deficiency, provides a potential pharmacologic and experimental tool to modulate FXIII-A2B2 activity.
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Plaquetas/metabolismo , Deficiencia del Factor XIII , Factor XIII/metabolismo , Factor XIIIa/metabolismo , Hemorragia/sangre , Animales , Factor XIII/genética , Deficiencia del Factor XIII/sangre , Deficiencia del Factor XIII/inducido químicamente , Deficiencia del Factor XIII/genética , Factor XIIIa/genética , Técnicas de Silenciamiento del Gen , Hemorragia/genética , Ratones , Ratones Noqueados , Nanopartículas , ARN Interferente Pequeño , ConejosRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel envelope virus that causes coronavirus disease 2019 (COVID-19). Hallmarks of COVID-19 are a puzzling form of thrombophilia that has elevated D-dimer but only modest effects on other parameters of coagulopathy. This is combined with severe inflammation, often leading to acute respiratory distress and possible lethality. Coagulopathy and inflammation are interconnected by the transmembrane receptor, tissue factor (TF), which initiates blood clotting as a cofactor for factor VIIa (FVIIa)-mediated factor Xa (FXa) generation. TF also functions from within the nascent TF/FVIIa/FXa complex to trigger profound changes via protease-activated receptors (PARs) in many cell types, including SARS-CoV-2-trophic cells. Therefore, aberrant expression of TF may be the underlying basis of COVID-19 symptoms. Evidence suggests a correlation between infection with many virus types and development of clotting-related symptoms, ranging from heart disease to bleeding, depending on the virus. Since numerous cell types express TF and can act as sites for virus replication, a model envelope virus, herpes simplex virus type 1 (HSV1), has been used to investigate the uptake of TF into the envelope. Indeed, HSV1 and other viruses harbor surface TF antigen, which retains clotting and PAR signaling function. Strikingly, envelope TF is essential for HSV1 infection in mice, and the FXa-directed oral anticoagulant apixaban had remarkable antiviral efficacy. SARS-CoV-2 replicates in TF-bearing epithelial and endothelial cells and may stimulate and integrate host cell TF, like HSV1 and other known coagulopathic viruses. Combined with this possibility, the features of COVID-19 suggest that it is a TFopathy, and the TF/FVIIa/FXa complex is a feasible therapeutic target.
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BACKGROUND: The cell membrane-derived initiators of coagulation, tissue factor (TF) and anionic phospholipid (aPL), are constitutive on the herpes simplex virus type 1 (HSV1) surface, bypassing physiological regulation. TF and aPL accelerate proteolytic activation of factor (F) X to FXa by FVIIa to induce clot formation and cell signaling. Thus, infection in vivo is enhanced by virus surface TF. HSV1-encoded glycoprotein C (gC) is implicated in this tenase activity by providing viral FX binding sites and increasing FVIIa function in solution. OBJECTIVE: To examine the biochemical influences of gC on FVIIa-dependent FX activation. METHODS: Immunogold electron microscopy (IEM), kinetic chromogenic assays and microscale thermophoresis were used to dissect tenase biochemistry. Recombinant TF and gC were solubilized (s) by substituting the transmembrane domain with poly-histidine, which could be orientated on synthetic unilamellar vesicles containing Ni-chelating lipid (Ni-aPL). These constructs were compared to purified HSV1 TF±/gC ± variants. RESULTS: IEM confirmed that gC, TF, and aPL are simultaneously expressed on a single HSV1 particle where the contribution of gC to tenase activity required the availability of viral TF. Unlike viral tenase activity, the cofactor effects of sTF and sgC on FVIIa was additive when bound to Ni-aPL. FVIIa was found to bind to sgC and this was enhanced by FX. Orientation of sgC on a lipid membrane was critical for FVIIa-dependent FX activation. CONCLUSIONS: The assembly of gC with FVIIa/FX parallels that of TF and may involve other constituents on the HSV1 envelope with implications in virus infection and pathology.
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Factor VIIa , Herpesvirus Humano 1 , Cisteína Endopeptidasas , Factor X , Proteínas de Neoplasias , Tromboplastina , Proteínas del Envoltorio ViralRESUMEN
Prothrombin complex concentrates (PCC) are fractionated plasma protein drugs that reverse warfarin anticoagulation. PCC may control more general bleeding. We sought to identify the dominant procoagulant factor in PCC in vivo. We tested PCC or coagulation factor (F) treatment in CD1 mice made coagulopathic by exchange of whole blood for washed red cells. Anesthetized mice were transfused with murine fresh-frozen plasma (mFFP), PCC, mixtures of human vitamin K-dependent proteins (VKDP) (prothrombin, FVII, FIX, or FX), or purified single human VKDP, immediately prior to tail transection (TT), liver laceration (LL), or intravascular laser injury (ILI). Plasma donor mice were treated with vehicle or control antisense oligonucleotide (ASO-CON) or ASO specific for prothrombin (FII) (ASO-FII) to yield mFFP or ASO-CON mFFP or ASO-FII mFFP. Blood losses were determined spectrophotometrically (TT) or gravimetrically (LL). Thrombus formation was quantified by intravital microscopy of laser-injured arterioles. PCC or four factor- (4F-) VKDP or prothrombin significantly reduced bleeding from TT or LL. Omission of prothrombin from 4F-VKDP significantly reduced its ability to limit bleeding. Mice transfused with ASO-FII mFFP demonstrated inferior haemostasis versus those transfused with ASO-FII following TT, LL, or ILI. Prothrombin is the dominant procoagulant component of PCC and could limit bleeding in trauma.
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Trastornos de la Coagulación Sanguínea/complicaciones , Trastornos de la Coagulación Sanguínea/etiología , Factores de Coagulación Sanguínea/farmacología , Transfusión Sanguínea , Hemorragia/tratamiento farmacológico , Plasma , Protrombina/farmacología , Animales , Coagulación Sanguínea/efectos de los fármacos , Factores de Coagulación Sanguínea/metabolismo , Modelos Animales de Enfermedad , Hemorragia/prevención & control , Ratones , Reacción a la TransfusiónRESUMEN
Essentials The coagulation initiator, tissue factor (TF), is on the herpes simplex virus 1 (HSV1) surface. HSV1 surface TF was examined in mice as an antiviral target since it enhances infection in vitro. HSV1 surface TF facilitated infection of all organs evaluated and anticoagulants were antiviral. Protease activated receptor 2 inhibited infection in vivo and its pre-activation was antiviral. SUMMARY: Background Tissue factor (TF) is the essential cell surface initiator of coagulation, and mediates cell signaling through protease-activated receptor (PAR) 2. Having a diverse cellular distribution, TF is involved in many biological pathways and pathologies. Our earlier work identified host cell-derived TF on the envelope covering several viruses, and showed its involvement in enhanced cell infection in vitro. Objective In the current study, we evaluated the in vivo effects of virus surface TF on infection and on the related modulator of infection PAR2. Methods With the use of herpes simplex virus type 1 (HSV1) as a model enveloped virus, purified HSV1 was generated with or without envelope TF through propagation in a TF-inducible cell line. Infection was studied after intravenous inoculation of BALB/c, C57BL/6J or C57BL/6J PAR2 knockout mice with 5 × 105 plaque-forming units of HSV1, mimicking viremia. Three days after inoculation, organs were processed, and virus was quantified with plaque-forming assays and quantitative real-time PCR. Results Infection of brain, lung, heart, spinal cord and liver by HSV1 required viral TF. Demonstrating promise as a therapeutic target, virus-specific anti-TF mAbs or small-molecule inhibitors of coagulation inhibited infection. PAR2 modulates HSV1 in vivo as demonstrated with PAR2 knockout mice and PAR2 agonist peptide. Conclusion TF is a constituent of many permissive host cell types. Therefore, the results presented here may explain why many viruses are correlated with hemostatic abnormalities, and indicate that TF is a novel pan-specific envelope antiviral target.
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Herpes Simple/virología , Herpesvirus Humano 1/metabolismo , Tromboplastina/administración & dosificación , Proteínas del Envoltorio Viral/administración & dosificación , Animales , Anticoagulantes/farmacología , Antivirales/farmacología , Modelos Animales de Enfermedad , Femenino , Herpes Simple/sangre , Herpes Simple/tratamiento farmacológico , Herpes Simple/inmunología , Herpesvirus Humano 1/efectos de los fármacos , Herpesvirus Humano 1/inmunología , Interacciones Huésped-Patógeno , Inyecciones Intravenosas , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor PAR-2/genética , Receptor PAR-2/metabolismo , Células TH1/inmunología , Células TH1/virología , Tromboplastina/metabolismo , Proteínas del Envoltorio Viral/metabolismoRESUMEN
Hemostasis is the physiological control of bleeding and is initiated by subendothelial exposure. Platelets form the primary vascular seal in three stages (localization, stimulation and aggregation), which are triggered by specific interactions between platelet surface receptors and constituents of the subendothelial matrix. As a secondary hemostatic plug, fibrin clot formation is initiated and feedback-amplified to advance the seal and stabilize platelet aggregates comprising the primary plug. Once blood leakage has been halted, the fibrinolytic pathway is initiated to dissolve the clot and restore normal blood flow. Constitutive and induced anticoagulant and antifibrinolytic pathways create a physiological balance between too much and too little clot production. Hemostatic imbalance is a major burden to global healthcare, resulting in thrombosis or hemorrhage.
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Coagulación Sanguínea , Hemostasis/fisiología , HumanosRESUMEN
Anticoagulant therapy-associated bleeding and pathological thrombosis pose serious risks to hospitalized patients. Both complications could be mitigated by developing new therapeutics that safely neutralize anticoagulant activity and inhibit activators of the intrinsic blood clotting pathway, such as polyphosphate (polyP) and extracellular nucleic acids. The latter strategy could reduce the use of anticoagulants, potentially decreasing bleeding events. However, previously described cationic inhibitors of polyP and extracellular nucleic acids exhibit both nonspecific binding and adverse effects on blood clotting that limit their use. Indeed, the polycation used to counteract heparin-associated bleeding in surgical settings, protamine, exhibits adverse effects. To address these clinical shortcomings, we developed a synthetic polycation, Universal Heparin Reversal Agent (UHRA), which is nontoxic and can neutralize the anticoagulant activity of heparins and the prothrombotic activity of polyP. Sharply contrasting protamine, we show that UHRA does not interact with fibrinogen, affect fibrin polymerization during clot formation, or abrogate plasma clotting. Using scanning electron microscopy, confocal microscopy, and clot lysis assays, we confirm that UHRA does not incorporate into clots, and that clots are stable with normal fibrin morphology. Conversely, protamine binds to the fibrin clot, which could explain how protamine instigates clot lysis and increases bleeding after surgery. Finally, studies in mice reveal that UHRA reverses heparin anticoagulant activity without the lung injury seen with protamine. The data presented here illustrate that UHRA could be safely used as an antidote during adverse therapeutic modulation of hemostasis.
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Antídotos/farmacología , Coagulación Sanguínea/efectos de los fármacos , Hemorragia/tratamiento farmacológico , Antagonistas de Heparina/farmacología , Animales , Anticoagulantes/efectos adversos , Hemorragia/inducido químicamente , Heparina/efectos adversos , Humanos , Pulmón/efectos de los fármacos , Ratones , Poliaminas , Polielectrolitos , Protaminas/efectos adversosRESUMEN
BACKGROUND: Dengue virus (DENV) is a transfusion-transmissible arbovirus that threatens blood donor systems with approximately 200 million high-titer asymptomatic infections occurring annually. Here we investigated the viability of DENV during storage of donor-derived platelet (PLT) and red blood cell (RBC) units. While purified PLTs have been shown to generate viable DENV, RBCs are replication incompetent. Combined with different storage criteria, distinct virus persistence profiles were anticipated in PLT and RBC units. STUDY DESIGN AND METHODS: Mimicking the virus titer of asymptomatic donors, purified DENV was spiked (10(5) -10(6) infectious units/mL) into PLT or RBC units produced and stored according to blood bank operating procedures. DENV was measured by infectious plaque-forming assays and by quantitative reverse transcription-polymerase chain reaction. RESULTS: In both PLT (7 days, 20-24°C) and RBC (42 days, 1-6°C) units, infectious DENV persisted throughout storage despite logarithmic decay. In buffer alone, DENV infectivity was insignificant by Day 1 at 20 to 24°C or 14 days at 1 to 6°C. Infectious virus production was identified in stored PLT units using a translation inhibitor and supported by virus genome replication. Surprisingly, DENV was also produced in RBC units, implying the involvement of cells other than RBCs. CONCLUSION: Both virus propagation and effects independent of cell function mitigate the intrinsic lability of DENV. Nevertheless, the overall rapid storage decay suggests that aged PLT and RBC units may be safer. These data raise awareness to the possible persistence of other conceivably more robust RNA viruses during the storage of cellular blood products.
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Plaquetas/virología , Conservación de la Sangre/efectos adversos , Virus del Dengue/crecimiento & desarrollo , Eritrocitos/virología , Virus del Dengue/aislamiento & purificación , Humanos , Cinética , Factores de Tiempo , Replicación ViralRESUMEN
Dengue virus (DENV) infection causes â¼200 million cases of severe flulike illness annually, escalating to life-threatening hemorrhagic fever or shock syndrome in â¼500,000. Although thrombocytopenia is typical of both mild and severe diseases, the mechanism triggering platelet reduction is incompletely understood. As a probable initiating event, direct purified DENV-platelet binding was followed in the current study by quantitative reverse transcription-polymerase chain reaction and confirmed antigenically. Approximately 800 viruses specifically bound per platelet at 37°C. Fewer sites were observed at 25°C, the blood bank storage temperature (â¼350 sites), or 4°C, known to attenuate virus cell entry (â¼200 sites). Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and heparan sulfate proteoglycan were implicated as coreceptors because only the combination of anti-DC-SIGN and low-molecular-weight heparin prevented binding. Interestingly, at 37°C and 25°C, platelets replicated the positive sense single-stranded RNA genome of DENV by up to â¼4-fold over 7 days. Further time course experiments demonstrated production of viral NS1 protein, which is known to be highly antigenic in patient serum. The infectivity of DENV intrinsically decayed in vitro, which was moderated by platelet-mediated generation of viable progeny. This was shown using a transcription inhibitor and confirmed by freeze-denatured platelets being incapable of replicating the DENV genome. For the first time, these data demonstrate that platelets directly bind DENV saturably and produce infectious virus. Thus, expression of antigen encoded by DENV is a novel consideration in the pathogen-induced thrombocytopenia mechanism. These results furthermore draw attention to the possibility that platelets may produce permissive RNA viruses in addition to DENV.
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Plaquetas/metabolismo , Virus del Dengue/fisiología , Dengue/metabolismo , Genoma Viral , Acoplamiento Viral , Replicación Viral , Moléculas de Adhesión Celular/metabolismo , Células Cultivadas , Dengue/virología , Citometría de Flujo , Humanos , ARN Mensajero/genética , ARN Viral/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas Virales/metabolismoRESUMEN
Developing bio-compatible smart materials that assemble in response to environmental cues requires strategies that can discriminate multiple specific stimuli in a complex milieu. Synthetic materials have yet to achieve this level of sensitivity, which would emulate the highly evolved and tailored reaction networks of complex biological systems. Here we show that the output of a naturally occurring network can be replaced with a synthetic material. Exploiting the blood coagulation system as an exquisite biological sensor, the fibrin clot end-product was replaced with a synthetic material under the biological control of a precisely regulated cross-linking enzyme. The functions of the coagulation network remained intact when the material was incorporated. Clot-like polymerization was induced in indirect response to distinct small molecules, phospholipids, enzymes, cells, viruses, an inorganic solid, a polyphenol, a polysaccharide, and a membrane protein. This strategy demonstrates for the first time that an existing stimulus-responsive biological network can be used to control the formation of a synthetic material by diverse classes of physiological triggers.